1. Sponges
Sponges are a diverse group of common types, with about 5000 species known across the world.
Sponges are primarily marine, but around 150 species live in fresh water.
Sponges have cellular-level organization, meaning that that their cells are specialized so that different cells perform different functions.
This is the simplest kind of cellular organization found among parazoans.

2. sponges include a system of pores (also called ostia) and canals, through which water passes.

3. Asconoid Example: Leucosolenia
*Sponges have three different types of body plans
Asconoid
sponges are shaped like a simple tube perforated by pores.
The open internal part of the tube is called the spongocoel.
There is a single opening to the outside, the osculum.
Example: Leucosolenia
Classification
Phylum : Porifera
Class : Calcarea
Order : Homocoela
Genus : Leucosolenia

5. Syconoid Phylum: Porifera Class : Calcarea Order : Heterocoe
Synconoid sponges tend to be larger than Asconoids.
The Synconoid body wall is thicker.
Example: Sycon
Classification
Phylum: Porifera
Class : Calcarea
Order : Heterocoe
Genus : Sycon

7. Leuconoid These are the largest and most complex sponges.
Example: Euspongia
Classification
Phylum: Porifera
Class : Demosongia
Order : Keratosa
Genus : Euspongia
Euspongia is the common bath sponge.
It is a deep sea form and is found in the Mediterranean Sea.
It is like a cup and the skeleton is made of sponging fibres.

9. Hydra can be white brown or green.
Classification:
Phylum: Coelentrata
Class : Hydrozoa
Order : Diploblastica
Genus : Hydra
Hydra can be white brown or green.
Hydra have a saclike body and a circle of tentacles at around the body opening.

10. This opening is used for both taking in food and eliminating wastes.
Hydra don't have eyes but they can sense light
They will also reproduce easily.
Hydra are carnivorous and will eat anything they can manage to catch including single celled animals, small crustaceans, worms, insects, and other tiny animals

13. Fasciola

14. Fasciola eggs

15. Fasciola intermediate host
Lymnaea sp.

16. Cercaria of Fasciola

17. The infective stage of Fasciola
Encysted metacercaria

18. Fasciola